Spring assembly for tank vehicles



June 0, 1941- Y R. A. BRADLEY ETAL 2,245,382

' SPRING- ASSEMBLY FOR TANK VEHICLES Filed Feb. 8, 1940 j'm'y. 1.

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Patented June 10, 1941 2,245,382 SPRING ASSEMBLY FOR TANK VEHICLE RalphA. Bradley and Doyle D. Buttolph, Kansas City, Mo., assignors to ButlerManufacturing Company, Kansas City, Mo., a. corporation of MissouriApplication February 8, 1940, Serial No. 317,847

Claims.

Our invention relates to a spring assembly for tank vehicles. r

A spring suificient to carry a heavy load must be provided in truck tankassemblies. Due to the fact that many State laws limit the total weightof the load which may be carried on the State roads, truck tankmanufacturers have designed truck tank constructions in which the tankitself is of comparatively light weight in order that the trucker mayincrease the pay load.

When the tank is empty there is excessive vibration due to the heavysprings which must be employed to carry the load when the tank is full.This vibration is the primary cause in most tank failures causingcrystallization of the metal of the tank and frequently leakage withensuing fire hazard where gasoline and oil are being carried.

One object of our invention is to provide a truck tank spring assemblyin which the tank when empty rides on a comparatively light spring,doing away with the destructive vibration which would otherwise takeplace with the empty tanks.

Another object of our invention is to provide a truck tank springassembly which will reduce the forward and backward motion of the axledue to spring deflection when the tank is loaded.

Still another object of our invention is to provide an assembly in whichthe need for grease is eliminated. I

A further object of our invention is to provide a spring assembly inwhich there is an ample load carrying capacity provided when the tank isfull, to reduce excessive tank sway.

A still further object of our invention is to provide a. spring assemblyin which a plurality of full length spring leaves act to position theaxle.

Other and further objects of our invention will appear from thefollowing description.

In the accompanying drawing which forms part of the instantspecification, and which is to be read in conjunction therewith, and inwhich like reference numerals are used to indicate like parts in thevarious views; I

Fig. 1 is a perspective view of a rear wheel assembly adapted to supportthe after end of a trailer or truck tank showing one embodiment of ourinvention.

Fig. 2 is a side elevation of the spring assembly of our invention.

Fig. 3 is an end view of the spring assembly shown in Fig. 2.

Fig. 4 is an enlarged sectional view taken on the line 4-4, Fig. 2.

In general, our invention contemplates the provision of chafing plateassemblies l, to which sills 2 are secured. The chafing plate assembliescarry upper chafing plates 3- and lower chafing plates 4. The surfacesof the chafing plates may be covered with a layer of mild steel 5.

The spring assembly comprises an upper light spring 6 and a lower heavyspring! clamped to the axle 8 by means of clamping U-bolts 9. A saddleI0 is positioned in the assembly over the axle and below the upperlight'spring 6, and is provided at one end with a bearing member II.

A pivot pin i2 is provided with rubber bushings l3, and pivotallyconnects a link H to the bearing I l The other end of the link I4 ispivotally secured in a bearing l6 by means of pin I'l. Rubber bushingsl8, similar to bushings l3, are positioned around the pin H. The upperlight spring is composed of a plurality of leaves IS, the upper two ofwhich are full length and rest against chafing plates 3. The weight ofthe empty tank is transmitted to the sills 2 thence to the chafing plateassemblies I; to chafing plates 3, to spring 6 and to the axle 8, andthence to the ground wheels.

When the tank is loaded the spring 6 will defiect, allowing the chafingplate assemblies I to move downwardly. When this occurs, the lowerchafing plates 4 will engage the full length leaves 20 of the lowerspring I, and the load will be thus borne by both springs 6 and l. Thelink I4 limits the motion and transmits the thrust of the ground Wheelsto the sills 2, in the case of a truck tank. In the case of a trailertank, the drag is taken up through the link and thus the spring assemblyis not displaced. The links l4 are built to withstand afar greaterstress than will ever be encountered in use. The arrangement is suchthat when the tank is loaded the links are practically level. Thisreduces to a minimum the forward and backward motion of the axle due tospring deflection under varying load conditions. The rubber mountingbushings l3 and I8 eliminate the need for grease and neutralizevibration. The upper spring has a very low carrying capacity so thatwhen the tank unit is empty, only the upper spring will carry the load,and enable the reduction or elimination of the destructive empty tankvibration. The lower spring I of maximum capacity comes into contactwith its chafing plates 4 only after the tank is loaded. The springs Iare sufiiciently'heavy to handle the full axle rating stopping excessivetank sway. The upper leaves of each spring extend through the chafingplate assemblies I. The width 01' the upper spring leaves is such thatthey are nearly the same as the interior dimension of the chafing plateassembly. This enables the steering of the axle to be done by the actionof the sides of the spring leaves on the sides of the chafing plateassembly.

The mild steel chafing surfaces 5 may be easily removed and replaced.This relieves wear on the chafing plate brackets and on the springsproper.

Opposite chafing plate assemblies are tied together by cross members 2|.This eliminates side movement due to the steering oi! the vehicle.

It will be seen that we have accomplished the objects of our invention.We have provided a novel spring assembly for truck and trailer vehiclesin which we are enabled to eliminate vibration with the tank empty, thusreducing to a minimum the principal cause of failure in the tankvehicles of the prior art.

It will be understood that certain features and sub-combinations are ofutility and may be employed without reference to other features andsub-combinations. This is contemplated by and is within the scope of ourclaims. It is further obvious that various changes may be made indetails within the scope of our claims without departing from the spiritof our invention. It

1. A spring assembly including in combination an axle, a nest oi springleaves above said axle,

a nest of spring leaves below said axle, means for clamping said springnests to said axle, vehicle body supporting means, chafing plateassemblies supporting said last named means, said chafing plateassemblies comprising upper ,chating plates and lower chafing plates,said upper spring nest normally contacting said upper. chaiing platesand supporting the load upon said axle, said lower spring nest normallypositioned out of contact with said lower chafing plates, a linkpivotally connecting said axle and one of said chafing plate assemblies,the arrangement being such that when a heavy load is supported by saidspring assembly, the upper spring nest will flex to permit the load tobe carried by said lower spring nest through said lower chafing plates.

2. A spring assembly as in claim 1 including in combination a pinsecured to said axle, a'pin secured to one of said chafing plateassemblies, said link formed with bearings at each end, said pinspassing through said bearings, and rubber bushings between each of saidpins and said bearings.

3. A spring assembly as in claim 1 in which said upper spring nest is ofsmaller capacity than said lower spring nest.

4. A spring assembly as in claim 1 in which chafing plate assemblies onopposite sides of the vehicle are interconnected by tie members.

5. A spring assembly as in claim 1 in which said link is substantiallyhorizontal when the load is borne by both spring nests.

RALPH A. BRADLEY. DOYLE D. BUT'IOLPH.

